Got a friend of mine who has a stock i5 750 and is thinking of moving to a i7 2600k, would it be a large difference? as in noticable in real world usage not just benchmarks the 750 is stock and the 2600k will be under water so i will help him overclock it

I would say depends on what he wants to do with it. If it is just for gaming, IMO, it is not worth it. If he is a folding fanatic and does other CPU intensive stuff such as rendering, etc. then it may very well worth it.

$150 would be an excellent deal, but he'd have to upgrade his motherboard too. If he just games it really wouldn't be worth upgrading it at the moment. I'd suggest he waits until Ivy Bridge is released.

he and i are both party of the intel retailedge program, ill be grabbing the 970 since its a drop in upgrade for me but he is thinking about getting the 2600k and i figured he could sell his current chip to offset some of that cost. either way the 2600k is gonna be cheap (and of course a new board)

What GPU does he have and what games does he play? SC2 is the only game I can think of that'd really benefit from that upgrade unless he's running SLI'd 580's on a 1920x1080 res. Also, HT is useless for games ATM.

And why are you upgrading to a 970? If it's a drop in, you already have, what, a 920/930? Buy a $50 cooler and OC your CPU instead (if your motherboard allows that).